Postnatal exposure to endosulfan interferes with the normal development of the male rat mammary gland

DELCONTE M; ALARCÓN R; MUÑOZ-DE-TORO M; ALTAMIRANO GA; MASAT E; LUQUE EH; GOMEZ AL; BOSQUIAZZO VL; KASS L

Congreso; LXI Reunión Anual de la Sociedad Argentina de Investigación Clínica, LXIV Reunión de la Sociedad Argentina de Inmunología y XLVIII Reunión de la Sociedad Argentina de Farmacología Experimental; 2016

Sociedad Argentina de Investigación Clínica, Sociedad Argentina de Inmunología y Sociedad Argentina de Fisiología Experimental

Endosulfan is one of the organochlorine pesticides that can act as an estrogen agonist and, it has been shown that stimulates the proliferation of the human mammary tumor cell line MCF-7 in vitro. The male rat mammary gland (MG) is sensitive to endocrine disruptors and, in the present study, our aim was to evaluate whether postnatal exposure to endosulfan modifies MG development in pre and postpubertal male rats. From postnatal day 1 (PND1) to PND7, male animals were injected subcutaneously every 48 h with: a) corn oil (vehicle, control) or b) 600 µg/kg body weight of endosulfan. On PND21 and PND60, blood and MG samples were collected. MG were processed for whole mount (WM) or paraffin embedded. Testosterone (T) serum levels, MG histo-morphology, collagen fibers organization, proliferation index, and the expression of estrogen (ESR1) and androgen receptor (AR) were evaluated. On PND21, MG area, perimeter, longitudinal growth and number of terminal end buds (TEBs) were higher in endosulfan-exposed than in control rats. Changes in histological sections such as alveolar development and increased presence of organized collagen in the stroma parallel those observed in the WM. Also, epithelial ESR1 expression was higher in endosulfan-exposed (42.7±1.7%) than in control rats (33.2±1.7%, p